# Rio Tinto Issues Conflicting Updates on Oyu Tolgoi Underground Operations.

By John Kim

Canonical URL: https://www.tokenpost.com/news/business/45036
Published: 2026-10-30T18:59:55.000Z
Updated: 2026-10-30T18:59:55.000Z
Section: Business

> A seismic event caused a localized rockfall and injured three employees; two continued receiving treatment for non-life-threatening injuries.

Rio Tinto said underground operations at its Oyu Tolgoi copper mine in Mongolia were progressively restarting in a Friday update, but a separate statement eight hours later said they were paused pending a safety review.

The company’s update at 7 a.m. ET (11:00 UTC) Friday, Oct. 30, described the restart as underway. The seismic event occurred at about 6 a.m. ET (10:00 UTC) Thursday, Oct. 29, and caused vibration underground.

The event caused no fatalities and injured three employees. Two employees continued to receive treatment for non-life-threatening injuries. The rockfall was confined to a temporary storage area beside the production zone and did not structurally affect the underground cave or operating infrastructure.

The company gave no timetable for completing the restart and no estimate of the event’s production impact. Oyu Tolgoi’s copper production rose 27% year over year in the third quarter, and the operation ran at an annualized rate of about 450,000 metric tons during the quarter.